1-Iodobuta-1,3-diynes in Copper-Catalyzed Azide–Alkyne Cycloaddition: A One-Step Route to 4-Ethynyl-5-iodo-1,2,3-triazoles

Abstract

Cu-catalyzed 1,3-dipolar cycloaddition of iododiacetylenes with organic azides using iodotris­(tri­phenyl­phos­phine)­copper­(I) as a catalyst was found to be an efficient one-step synthetic route to 5-iodo-4-ethynyltriazoles. The reaction is tolerant to various functional groups in both butadiyne and azide moieties. The synthetic application of 5-iodo-4-ethynyl triazoles obtained was also evaluated: the Sonogashira coupling with alkynes resulted in unsymmetrically substituted triazole-fused enediyne systems, while the Suzuki reaction yielded the corresponding 5-aryl-4-ethynyl triazoles.

Design and Synthesis of New 5-aryl-4-Arylethynyl-1H-1,2,3-triazoles with Valuable Photophysical and Biological Properties

“…These compounds are also easily available due to CuAAC, then the 1-idoacetylenes are used instead of terminal acetylenes [ 33 , 34 ]. Earlier, the possibility to involve 1-iodobuta-1,3-diynes in CuAAC and modification of obtained 4-ethynyl-5-iodo-1,2,3-iodotriazoles in cross-coupling reactions were shown by our research group [ 35 ].…”

Transition Metal‐Catalyzed Cycloaddition of Azides with Internal Alkynes

“…The [CuI(PPh 3 ) 3 ]/2,6‐lutidine system still shows high activity at lower metal loadings. It's also effective in catalyzing the cycloaddition of 1‐iodobuta‐1‐3‐diynes 9 with organic azides, which is a convenient route to prepare 4‐ethynyl‐5‐iodo‐1,2,3‐triazole skeletons (Scheme 6d) [16] . Chen et al.…”

Regioselective Synthesis of Halotriazoles and their Utility in Metal Catalyzed Coupling Reactions

“…The method gave ready access to the 1,2,3‐triazoles 130 with unsymmetrically substituted enediynes, even with substrates having functional groups such as alcohols and substituted amines, in high yields. [ 56 ]…”

“…The 5‐iodo‐ N ‐(4‐methoxyphenyl)triazole 172d provided the Suzuki coupling product 174d in low yield. [ 56 ]…”